| 董伟,张利花,吴智敏.岩石-混凝土界面拉伸软化本构关系试验研究[J].水利学报,2014,45(6): |
| 岩石-混凝土界面拉伸软化本构关系试验研究 |
| Experiment study on tension softening constitutive relation of rock-concrete interface |
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| DOI： |
| 中文关键词: 岩石-混凝土界面 轴向拉伸 三点弯曲梁 粗糙度 软化本构 |
| 英文关键词: rock-concrete interface uniaxial tension three-point bending roughness softening constitutive |
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| 中文摘要: |
| 对岩石-混凝土界面试件进行了轴向拉伸和三点弯曲梁试验，研究粗糙度对界面断裂特性的影响，建立了界面软化本构关系。以界面粗糙度为参量，结合界面三点弯曲试验所得的荷载-位移曲线，采用改进的J积分法计算裂缝扩展的能量损耗，建立了基于虚拟裂缝黏聚力能量守恒关系。通过归一化拟合建立的挠度、裂缝张开宽度及裂缝扩展长度关系，最终确定了岩石-混凝土界面的拉伸软化本构曲线，并提出指数型和双线型的黏聚力表达式。试验和计算结果表明：岩石-混凝土界面单轴抗拉强度、断裂韧度及断裂能随着界面粗糙度的增加而增大。本文所得的界面软化本构关系只与界面抗拉强度和断裂能有关，可以应用于不同粗糙度界面的断裂计算中。 |
| 英文摘要: |
| Laboratory tests， including uniaxial tension and three-point bending， were conducted on rock-concrete composite specimens to investigate the effect of interface roughness on interface fracture behavior and to establish interfacial softening constitutive relation for various degrees of interface roughness.Based on the load-displacement curves measured in three-point bending tests， the energy dissipation can be derived through modified J-integral method. The energy balance during crack propagation can be established， i.e. the energy dissipation is equal to the energy caused by fictitious cohesive force acting on fracture process zone. Using the results of δ， w and a from experiment， which are normalized by the maximum and fitted values， tension softening constitutive expression of rock-concrete interface model has been obtained. Experimental and calculated results indicate tensile strength， fracture toughness and fracture energy of rock-concrete interface increase with the increase of interface roughness. Meanwhile， the expression of interfacial softening constitutive curve can be determined through measuring two parameters， i.e.， interface tensile strength and interface fracture energy， which can be applied on fracture analysis of rock-concrete interface with various roughnesses. |
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